[PATCH v2] malloc: fix allocation for a specific case with ASAN

[Artur Paszkiewicz <artur.paszkiewicz@intel.com>]

Allocation would fail with ASAN enabled if the size and alignment was
equal to half of the page size, e.g.:

size_t pg_sz = 2 * (1 << 20);
rte_malloc(NULL, pg_sz / 2, pg_sz / 2);

In such case, try_expand_heap_primary() only allocated one page but it
is not enough to fit this allocation with such alignment and
MALLOC_ELEM_TRAILER_LEN > 0, as correctly checked by
malloc_elem_can_hold().

Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
---
v2: 
- fix commit message typo

 lib/eal/common/malloc_heap.c | 4 ++--
 lib/eal/common/malloc_mp.c   | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/eal/common/malloc_heap.c b/lib/eal/common/malloc_heap.c
index 6b6cf9174c..bb7da0d2ef 100644
--- a/lib/eal/common/malloc_heap.c
+++ b/lib/eal/common/malloc_heap.c
@@ -402,8 +402,8 @@ try_expand_heap_primary(struct malloc_heap *heap, uint64_t pg_sz,
 	int n_segs;
 	bool callback_triggered = false;
 
-	alloc_sz = RTE_ALIGN_CEIL(RTE_ALIGN_CEIL(elt_size, align) +
-			MALLOC_ELEM_OVERHEAD, pg_sz);
+	alloc_sz = RTE_ALIGN_CEIL(RTE_MAX(MALLOC_ELEM_HEADER_LEN, align) +
+			elt_size + MALLOC_ELEM_TRAILER_LEN, pg_sz);
 	n_segs = alloc_sz / pg_sz;
 
 	/* we can't know in advance how many pages we'll need, so we malloc */
diff --git a/lib/eal/common/malloc_mp.c b/lib/eal/common/malloc_mp.c
index 7270c2ec90..62deaca9eb 100644
--- a/lib/eal/common/malloc_mp.c
+++ b/lib/eal/common/malloc_mp.c
@@ -250,8 +250,8 @@ handle_alloc_request(const struct malloc_mp_req *m,
 		return -1;
 	}
 
-	alloc_sz = RTE_ALIGN_CEIL(RTE_ALIGN_CEIL(ar->elt_size, ar->align) +
-			MALLOC_ELEM_OVERHEAD, ar->page_sz);
+	alloc_sz = RTE_ALIGN_CEIL(RTE_MAX(MALLOC_ELEM_HEADER_LEN, ar->align) +
+			ar->elt_size + MALLOC_ELEM_TRAILER_LEN, ar->page_sz);
 	n_segs = alloc_sz / ar->page_sz;
 
 	/* we can't know in advance how many pages we'll need, so we malloc */
-- 
2.35.3